Field of the Present Disclosure
Embodiments of the present disclosure relate generally to the field of semiconductor devices. More specifically, embodiments of the present disclosure relate to dynamic on-die terminations (ODT).
Description of Related Art
A semiconductor device, such as a microcomputer, memory, gate array, among others, may utilize on-die termination (ODT). Activation of the ODT may interfere with some operations (e.g., a memory READ) but may enhance other operations (e.g., a memory WRITE). Thus, the ODT may be dynamically activated using one or more signals, RTT, that is asserted based on various factors. For example, RTT may include one of four types: 1) RTT-PARK a non-command-based that at any time enabled in a mode-register, 2) Dynamic RTT that happens with a WRITE command, 3) WR-Nominal-RTT happens with a non-target WRITE command, and 4) RD-Nominal-RTT happens with a non-target READ command. All of these modes can produce ODT at a data pin (DQ). For a READ operation, all of these types of RTT may be disabled during the read-burst to prevent causing a conflict at the DQ. In some embodiments, there may be a priority list that determines which type of RTT has precedence overall and/or in certain conditions. For example, in some embodiments, RTT-PARK may have a lowest priority while an RTT-OFF (ODT disable) during a READ has the highest priority.
In some embodiments of a memory device, the RTT signal may be asserted to create a dynamic RTT window based on a cas-write-latency (CWL), a cas latency (CL), a burst-length of data, a write preamble, and/or latency-independent. CL is the column access strobe latency that is the delay time between when a memory controller tells the memory module to access a particular memory column and when the data in given array location is available. Moreover, the CWL is a period of time from when a WRITE command is asserted to the input of the first data in a number of clock cycles. However, this timing may be very rigid to prevent the dynamic RTT window from being active during other operations (e.g., READ operation) that may be negatively effected by RTT being active.
Embodiments of the present disclosure may be directed to one or more of the problems set forth above.